Floating-point arithmetic operations are widely used in digital applications such as Central Process Unit (CPU), Digital Signal Processor (DSP) and/or the like. A real number can be written in floating-point representation. For example, a real number ‘a’ can be expressed by the following equation:a=(−1)S·Ma·bq   (1)where S is the sign of the real number ‘a’; Ma is the mantissa of the real number ‘a’; b is the base (2 or 10) of the real number and q is the exponent of the real number ‘a’.
Floating-point arithmetic operations such as an increment/decrement process may be carried out by a variety of logic circuits. For example, an increment process may be carried out based on an adder having a first input configured to receive a number to be increased by 1 and a second input configured to receive a binary number, which is set to 1. On the other hand, for a decrement process, the data of the first input is added to the second input whose value is set to −1. The two n-bit binary numbers are processed by the adder to generate an (n+1)-bit output. In general, the computation delay of the increment/decrement operation based upon an adder (e.g., a ripple adder) is (n−1) levels of logic gates.